The long-term objective of this research is to investigate the effects of tai chi chuan on symptoms of anxiety and sleep quality in young adults. Anxiety disorders are estimated to affect 25% of the population over the lifetime and are associated with significant personal, social and economic costs. People with poor sleep quality are 1.97 to 6.3 times more likely to develop anxiety disorders and 4.0 times more likely to develop psychiatric disorders in general (Taylor, Lichstein, & Durrence, 2003). Adolescence and young adulthood are key times for development of early signs of anxiety disorders. Cognitive-behavioral and pharmacological interventions are available for treatment of anxiety, but the diagnosis of a mental illness carries a stigma that keeps many young people away from these standard treatments. Exercise is a promising low-cost intervention with minimal negative side effects that is an alternative treatment for anxiety and poor sleep quality. A recent meta-analysis found moderate effect sizes for physical exercise interventions on symptoms of anxiety, but the means by which exercise has these effects remains largely unknown (Wipfli, Rethorst, & Landers, 2008). [Specifically for tai chi chuan, another recent meta-analysis found moderate effect sizes on symptoms of anxiety (Wang et al., 2010).] Brosschot, Gerin, and Thayer (2006) hypothesized that perseverative cognition moderates the health consequences of stressors because it can prolong stress-related affective and physiological activation. They define perseverative cognition as repetitive thoughts containing a representation of one or more psychological stressors. Based on their theory, we propose two processes through which the mindful exercise practice of tai chi chuan may ameliorate the effects of stress and symptoms of anxiety: (1) cognitively by reducing perseverative cognition and improving psychological functioning, and (2) physiologically by reducing chronic physiological arousal. [We propose a randomized controlled trial comparing tai chi chuan with a stress management education group on changes in anxiety and sleep quality. The primary aim of this study is to determine the feasibility of a protocol to compare the effects of these two groups including our recruitment, screening, randomization, retention, and measurement methods. The secondary aim of this study is to elucidate psychobiological processes associated with reductions in symptoms of anxiety and improvements in sleep quality. Targeted biomarkers are salivary cortisol, salivary alpha-amylase, and cardiac autonomic modulation. Information about the response of anxiety and sleep quality to tai chi chuan will be valuable in formulating treatment recommendations for young adults. PUBLIC HEALTH RELEVANCE: Adolescence and young adulthood are key times for development of early signs of anxiety disorders. Cognitive-behavioral and pharmacological interventions are available for treatment of anxiety, but the diagnosis of a mental illness carries a stigma that keeps many young people away from these standard treatments, and pharmacological interventions can have negative side effects. Information about who responds to tai chi chuan will be valuable in formulating treatment recommendations for young adults with symptoms of anxiety and attendant poor sleep quality.